Device for measuring the thickness of thin layers

摘要

For the purpose of measuring layer thickness using the fluorescence principle, the beam is directed through a deflecting mirror onto the specimen. A laterally attached microscope can be used to view the measuring point via the deflecting mirror, since the deflecting mirror brings the optical axis together with the beam axis. In order also to be able reliably to excite materials having a low atomic number, for which corresponding low-energy radiation is to be used, it is proposed to provide the deflecting mirror 46 with a small hole 112 which is aligned with the beam axis 32. This results in eliminating the attenuation of the radiation in the glass of the deflecting mirror, which is noticeable virtually only in the lower energy spectrum. <IMAGE>